i
:5:
i9:
:
ii~.
,!i
!ii~
iii!
iiii~ii~~i
iiii~ii
J;;
mbraced by the U-shaped
lifting vessel Ostrea, a
finished pier is hoisted
by towering gantry cranes
(above, at bottom left) from
the island of Neeltje Jans. The
construction dock's three pier
compartments were built 15
meters below sea level to allow
for flooding and towing of the
piers to the placement sites.
There the Macoma was coupled
to Ostrea's stern to maintain
a precise position. Aboard the
Ostrea a computer (farright)
indicates her location, as well
as information on winds and
currents. On shore, other
guidance equipment (right)
enables the pier to be lowered
1ij
iii
into position with no more
than ten centimeters of error.
The 150-acre work island
contains a power station and
computer control center for the
operation of the gates. The
Dutch government is
considering a proposal to use
Neeltje Jans as an exhibition
center for the Delta Project.
National Geographic,October 1986
;:I
+ir
,
ri
534